February 26, 2021 | New diagnostics for both SARS-CoV-2 and antigens Plus: how protected are we by prior infections?
Research Updates
Researchers at NCI collaborated with two healthcare data analytics companies (HealthVerity and Aetion) and five commercial laboratories to look at how protected individuals are by a prior SARS-CoV-2 infection. In cohort study of more than 3.2 million US patients with a SARS-CoV-2 antibody test, 0.3% of those indexed with positive test results had evidence of a positive nucleic acid amplification test beyond 90 days after index, compared with 3.0% indexed with negative antibody test results. They published their findings in JAMA Internal Medicine. DOI: 10.1001/jamainternmed.2021.0366
University of Minnesota Medical School researchers have developed two new rapid diagnostic tests for COVID-19 using the CRISPR/Cas9 system. They integrated commercially available reagents into a CRISPR/Cas9-based lateral flow assay to detect SARS-CoV-2 sequences with single-base specificity. This approach requires minimal equipment and represents a simplified platform for field-based deployment, the authors recommend. They also developed a rapid, multiplex fluorescence CRISPR/Cas9 nuclease cleavage assay capable of detecting and differentiating SARS-CoV-2, influenza A and B, and respiratory syncytial virus in a single reaction. They published their work in Bioengineering. DOI: 10.3390/bioengineering8020023
Industry Updates
PerkinElmer has launched the PerkinElmer COVID-19 Antigen Test for the qualitative detection of SARS-CoV-2 nucleocapsid protein antigen in nasal (NS) or nasopharyngeal (NP) swab specimens. The lateral flow immunoassay test can be used to screen or to aid in diagnoses of COVID-19 in asymptomatic or symptomatic individuals. A positive or negative result can be obtained in as little as 15 minutes to facilitate immediate isolation or treatment decisions. The in vitro diagnostic device is ideally suited for professional use point-of-care (POC) clinical and non-clinical settings such as healthcare centers, travel hubs, businesses and educational institutions. Clinical studies in symptomatic and asymptomatic populations, including individuals with low viral load, have shown sensitivity of greater than 97% among all NS and NP samples. Specificity of the test across 202 negative samples was 100%, which means no false positives were identified. Press release.
GenMark Diagnostics announced that its ePlex Respiratory Pathogen Panel 2 (RP2) is predicted to detect known SARS-CoV-2 variants currently in circulation. The recently identified SARS-CoV-2 variant strains include multiple mutations with the majority occurring in the spike protein, or S gene region and additional mutations found in the nucleoprotein region, or N gene. The ePlex RP2 Panel targets two unique regions of the N gene; the currently identified N gene mutations for the variants listed above are found outside of the sequence region targeted by the SARS-CoV-2 assays on the ePlex RP2 Panel and therefore the following variant strains currently in circulation are predicted to be detected based on the in silico analysis: B.1.1.7 (UK), B.1.351 (South Africa) , P.1 (Brazil), COH.20G/677H and COH.20G/501Y (Ohio, USA) and B.1.429 (California, USA). Press release.
LightDeck Diagnostics announced today that it has been awarded a $5.65 million contract from the Biomedical Advanced Research and Development Authority (BARDA), part of the Office of the Assistant Secretary for Preparedness and Response at the US Department of Health and Human Services (HHS), to develop a rapid antigen test to detect SARS-CoV-2. These funds will enable LightDeck Diagnostics to develop a point-of-care antigen test that delivers results in less than 6 minutes. The LightDeck COVID-19 Antigen Test leverages the highly sensitive and simple test procedure of waveguide technology with cost-effective manufacturing techniques to deliver an accurate, scalable test. The LightDeck antigen test will be a significantly faster alternative to the current PCR based diagnostic tests and offer better sensitivity and specificity than the available lateral flow-based tests that require at least 15 minutes to deliver results. Press release.
Vocalis Health has announced results of a clinical study conducted in collaboration with the Municipal Corporation of Greater Mumbai (MCGM) at their NESCO COVID-19 Center to validate Vocalis Health’s COVID-19 screening tool, VocalisCheck. VocalisCheck is a software-only product that can be accessed via smartphones or other devices. Users simply count from 50 to 70, their voice recording is transformed to a picture (spectrogram) containing 512 features. That picture is then compared using AI machine learning/deep learning techniques to a composite picture based upon the voice recordings of COVID-19 positive participants in clinical trials to determine whether there is a high or low correlation between them. The MCGM study included over 2,000 participants who spoke numerous languages including English, Hindi, Marathi and Gujarati. Results from an unblinded validation set of 288 participants demonstrated an AUC of 0.88, which translated to accuracy of 81.2%, sensitivity of 80.3% and specificity of 81.4%. VocalisCheck has also obtained a CE mark. VocalisCheck is the first device with CE mark approval for its medical intended use of screening for COVID-19. Press release.